Samuel crow



No. 6I2,706. Patented Oct. I8, |398. S. CROW. CUMBINATIUN DHEDGE FORMINING FOR AND SAVING GOLD, TIN, AND DTHER METALS.

, (Ap'plicadgion ld Aug. 4, 188.7. N o M o d e I ma Norms ravens co,noauwo., WASHINGTON. o, c.

countant, a subjeetor :the Queen of Great Britain, residing at 31 MorayPlace, in the f1., ing Gold,Tin, orA other Metals, of which the .Y at ahigher level than the bottom of the padtoons or by means ofV jib-cranesor the like.

SAMUEL cEow, or DUNEDIN, NEw ZEALAND.

COMBINATION-uriner FoRwNlNe For AN D SAvlNe GOLD, uN4J 0R OTHER METALS.

S'PEQIFICATION forming part of Letters Patent No. 612,706, dated Octobery18, 1898.

Application filed August 4L, 1897. i

To afZZ wwiiz it 77mg concern: i

ille-it known that I, SAMUEL CROW, an ac city of Dunedin, in the BritishColony of New Zealand have invented a new and useful Combination-DredgeVfor Mining for and Savfollowing is a specification.

The object of this invention is to mine and treat an alluvial paddockand to clean up the bottom of samein order to obtain the gold, tin,orther metals in theWash-dirt, crevices, and bottom. A

A dredge is made in the usual Way for bucket-dredging and is alsoprovided with sand-pumps. Vhen dredging With buckets, the largest of`these pumps `is usedfor elevating the tailings and the rest for liftingthe Water or wash-dirt. f The following is a general description of the:manner in Which I eiiect my working:V

A paddock is dredged to as near the bottom as possible, and part or aspace beyond the paddock is cut to a sufficient depth and size tocontainthe dredge when the paddock is pumped out, sothat the dredge isretained dock. y.

During the dredging of the paddock the tailingsepipe will sometimes haveto be of a" great length to clear the edges of the paddock. This pipeWill either be supported on pon- Dams may have to be formedv when in ornear a body of waterto allow of the subsequent draining of the paddock.lVhen the paddock is drained or pumped out, it is sluieed by nozzleswith Water supplied from a well in the dredge or other available sourceto the suction of one ofthe sand-pump s,which discharges the wash-dirtthus obtained into .l a perforated revolving screen furnished with holesof graded size,l the smaller holes being at the upper4 end of thescreen. Vhen the buckets are being used for lifting, the washi dirt isdelivered into`thissame screen. The Wash-dirt so delivered into theupper end of the screen is separated thus: The portions too coarse forpassing through any of the `holes in the screen pass over a coarse grid,and then the very coarse pieces go overboard i Serial No. 647,091. (Nomodel.)

andthe rest drop into aboX, while the graded portion which Ahas passedthroughthe holes in the screen spreads over savingtables,pref

erably covered with ripples of expanded metal, and then drops into aWell. This washdirt is then elevated into adistrib'uting-box,

where it is 'again spread over tables and return-tables to savedeck-space. Any of the tables may be provided with se1f-cleansingtraveling 1n atting's, so as to present a cleansed surface to thedescending Wash-dirt. From these tables the wash-dirt passes to thetailrace, which leads it past the `well at the foot of the iirst tablesunder the screen, so that when' desired the wash-dirt can be turnedagain into this'Well, and the saving process can thus be repeated, orelse the Wash-dirt is allowed to pass to the tailings pump or elevator.j' l W'ater for washing down the tables is drawn in by one of the pumpsarranged for this Work, and a branch from the pump suction-pipe drainsthe well when required, or. the Well may be allowed to overflow to thetailingspu1np,which is obviously the largest one.

When the bottom of the pumped-out paddock is being cleaned up, thebuckets are not in use,V and as the ,dredge may then for conveniencesake have been grounded the usual Iplacc of intlowforcirculating waterto cool fthe condenser ywould be ineffective, and so to furnish thisWater a connection may be taken from the well inside the dredge.

Any of the'boxes, tables, or tail-race may be furnished lwith suchsuitable saving appliances as are usually used.

Referring to the accompanyingdrawings, Figure lis a plan of adredge-With the apparatus as arranged for my manner of working. Fig. 2is a part elevation and part section of same with the sides of` thetables and boxes removed to show same' better.

A A is the punt or hull of any dredge, and A is the bucket-well forf theline of buckets to Work in for dredging. y

' B is the position of the usual line of dredging-buckets in abucket-dredge, and B' is the main upper tumbler.l f`

C is any condenser as used for compound engin es and is shown merely toillustrate the arrangements for the water circulation under theconditions in `which the dredgelmay be.

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\ D is the main intakeor suction pipe of the wash-dirt and water pump D.The discharge is usually through the pipe D to the pipe F in thecylinder E. The pipe F is perforated -with fine holes in that part whichis inside the cylinder E and is used when water is pumped by D forwashing the wash-dirt brought by the buckets B when they are Working;but it is changed for a plain pipe (also F) simply discharging from theupper end when the pump D is delivering wash-dirt and water and thebucketsB are thrown out of gear.

E is a revolving perforated screen usually running on small rollers, asshown, and set at an angle for free delivery, at the lower end, 'of thewash-dirt that cannot be screened.

This screen is slowly revolved, usually by tooth wheels, as shown. Thesupportingwheels may, however, be larger and flanged, asrailway-\vheels, and the power can then be applied to some of thesewheels to cause the cylinder to revolve slowly, the flanges merelypreventing the tendency of the screen to slide down during itsrevolutions. This cylinder is perforated with graded holes between vtheroller-paths, the smallest perforations being at e, the holes becominglarger in the direction of e and being largest at e.

ered by the buckets B, in which case the water for washing same isdelivered by the pump D into the perforated pipe F and through thedelivered at the top of the plain pipe F by the pump D', the wash-dirtis screened through the graded holes in the screen E, and the combinedwash-dirt and water for washing pass together over the tables G to thewell H H. Any wash-dirt too coarse to go through the screen-holes passesover the bar-grid Lwhich separates it, so that the iiner wash-dirt dropsinto the box J, the coarser sliding overboard on the plate I, thusavoiding the choking of the pump K. As the well H H would soon be fullof wash-dirt and especially of water, the surplus Water may be drawn offby the pipe G'. The amount so drawn off can be regulated by a stop cockin the pipe G. Should it be found desirable, the whole of the water canbe sent over the tables through the pump D by way of the screen E, orpart or all may be allowed to escape through the opening S to the tail-race R' vand so to the tailingsdischarge pump K by the pipe K. Thewash-dirt in the well H H gravitates to the foot of the elevator L,which takes it to the distributing box M, together with the smallquantity of water which may have been well A -or from the well H, if thesupply from g A fails, by the pump L" and is supplied through theperfor-ations of the pipe L'. The

Wash-dirt then passes over the saving-tables N, and it will be seen thatin this operation the desired quantity of water can be used and there isno compulsion touse the larger quantity of water that is required forscreening, which larger quantity would tend to prevent the lodgment andsaving of the gold, tin, or other metals. From N the wash-dirt passes tothe box O and to the under tables P, on

. which the matting slowly travels in a direction contrary to the flowof the wash-dirt.

IThis matting is constructed as an endless band having the lower partmoving in a trough of water,where it can be brushed by a revolving brushQ to remove the concentrates collected on the matting, thus enablingthe` mattn g to present a cleansed surface to thewashdirt coming fromthe box O. Passing through the-box R to the tail-race R the Wash-dirtcan, if desired, at any time be directed through ythe opening or by-washS, and thus returned to the well H to be re-treated over the tables Nand P. Otherwise the wash-dirt passes to J, where it is pumped by thepump K' to the tailings through the pipe K. When it is desired to repassany of the wash-dirt through any of the processes, the dredging can bestopped, or partly so, by the buckets or pumps j being stopped orslowed. In working whether the wash-dirt is delivj- When the dredge isused as a bucket-dredge to cut the paddock out, the pumps Dl and K' areused. The pump L" is used when the enigines are running; but if thewatery is not ,required to pass over the table N it can be turnedoverboard by any branch. (Not shown.)

lf at any time it is found that the buckets cannot reach low enough inthe paddock then f being worked, a suitable depth can be obtained byreducing the inflow of water to the paddock. Then the discharge-pumpfrom K Will reduce the Water and give the depth required. The partdredged outside and adjoining the paddock on which the dredge is Vto beiioated to and secured must only be of suinpumps to work effectively.For the purpose of pumping the paddock after excavation by the dredgeall the pumps can be used. The water pumped by the pump D' will beturned into K by opening the valve in the pipe G", the pump K will drawthroughthe branch T on opening the valve in branch T and placing a blindflange on the end of the pipe in the box J., and the pump L" will drawthrough the branch U, generally used for sluicing, by closing the Valvein the pipe G' and also closing the end of the pipe that is under thetables G by a blind flange. The pipes D, K, and T may be swiveled in anydirection to suit circumstances. In subsequently cleaning the bottom thewell H is supplied with water, T is stopped, and for sluicing water isallowed to fall bygravitation from U. Washdirt is drawn in at D, passingto the screen and other saving processes as described, the tailingspassing away at K.

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In this invention any suitable materials,

sizes, or grades may he adopted.

What I claim as my invention, and desire to obtain by Letters Patent ofthe United States, is-

1. In a combined dredge and ore-concentrator, the combination of a boat,means for elevating the material operated upon supported on said boat, agraded screen into which said dredge discharges, a Water-pipedischarging into said screen, separating-tables located underneath saidscreen, a we into which `Said tables discharge, an elevat` in said Well,a separatingtable upon which. said elevator discharges, an endless apronprovided with matting upon which said table discharges anddischarge-troughs whereby the tailings may be delivered either to thetailings-pump or to the well, substantially as described.

2. In a combined dredge and ore-concen-V trator, the combination of aboat, a dredge supported on said boat, a graded screen into which saiddredge discharges, a Water-pipe discharging into said screen,separating-tables underneath said screen, a Well into which said tablesdischarge, means for removing the surplus Water from said Well, anelevator in said Well, a separating-table into which said elevatordischarges, an endless apron provided With matting upon which said tabledischarges, a revolving brush for cleanin g said atting, anddischarge-troughs, whereby the ailin gs may be led directly to thetailingspnmp or back to the Well for retreatment, substantially asdescribed.

SAMUEL CRUWV.

W'itnesses:

I-IENTON MfrcAUL-AY DAvEv, CHARLES EDWIN DAvEY.

